1. Field of the Invention
This invention relates generally to the field of roll or cylinder grinding machines and, more particularly, to a measuring assembly or caliper assembly utilized to measure the geometry or configuration of rolls or cylinders received on grinding machines.
2. Description of Related Art
Rolling mills in the steel, aluminum and paper industries commonly use metal rolls in shaping products, such as a piece or sheet of metal, aluminum foil, or sheet of paper. The rolls may have a surface cover of a material other than metal, such as rubber, polyurethane or ceramic. Use in the mill eventually leads to a degradation of shape and quality of the roll surface, at which point one must take the roll out of the mill for refinishing on a grinding machine. U.S. Pat. No. 4,811,524 to Corallo describes a grinding machine.
U.S. Pat. No. 6,159,074 to Kube et al. describes a caliper assembly for a grinding machine. This caliper has two measuring arms used to measure the diameter of the roll in the grinding machine. A series of consecutive diameter measurements along the length of the roll provides the roll profile.
A common problem with roll grinding stems from inaccuracies in the mechanical support of the roll which induce extraneous error movements of the roll as the roll turns. Without compensation in the grinding process, these error movements may contribute to roundness or shape errors in the finished roll.
A two-point measurement cannot reliably distinguish roundness or shape errors from error movements of the roll.